Each year around 785,000 Americans endure a first myocardial infarction (MI) and 470,000 will have a recurrent event. The American Heart Association (AHA) recommends exercise-based cardiac rehabilitation (CR) for reductions in subsequent cardiac events. Despite the benefits of CR, only 14-35% of eligible MI patients participate in CR. Patients with co-morbidities, women, older adults, and ethnic minorities are least likely to utilize CR services. Many medical centers do not have CR programs and patients have to travel to distant locations to undergo CR. In turn, many Tai Chi interventions, have been studied in elderly cohorts, require no expensive equipment, can be practiced at home, and is well tolerated across fitness levels, and co-morbidities. Tai Chi increases heart rate (56% to 65% of maximum), oxygen consumption and lactate accumulation, signifying that Tai Chi serves as an aerobic exercise of low to moderate intensity. However, no Tai Chi studies in post-MI patients have employed state-of-the-art measures of cardiac function and exercise capacity and therefore it is unclear whether Tai Chi has similar benefits as CR during a period of myocardial recovery. The proposed study would employ tools including echocardiograms, heart rate recovery, and bicycle ergometry, which have been used in many CR studies to assess the effectiveness of treatment. This study is also innovative in that it specifically targets patients who have not opted to participate in a formal CR program within 30 days of a first-time MI and emphasizes recruitment of patients spanning an older age range, physical function ability, women and minorities. A total of 75 men and women with a first time MI will be randomly assigned to 4 months of Tai Chi training composed of 20 meditative movements or to standard of care (SOC). Clinical assessments will be performed over a six-month period, with testing occurring before, mid-way, and after 4 months of treatments, and at an 8 week follow-up. Our current goal is to gather preliminary data on study feasibility, acceptability and to find indicatins of improvements in physical, cardiac and psychological/behavioral factors. If the aims are met from this exploratory/development study, a future large scale study will be undertaken to confirm Tai Chi's efficacy in post-MI patients. Such research is critically needed so adequate rehabilitative interventions can be developed for diverse MI patients.